The present invention relates to the field of disturbance free update of data, in particular to the field of disturbance free update of software and related data in a software processing device and also a method adapted thereto.
The evolution of data processing equipment and software technology leads to an increasing demand for methodologies to update software.
The usual methodology to achieve this goal is to stop the execution of the installed software, load the new software and then start the new software. Using this approach, no internal data is transferred between the old and the new software. Also, with this method all the established services are lost and all service is completely stopped during the load and start of the new software. Currently, this method is typically used for, e.g., work stations or personal computers.
Another method is to load the new software while the old software continues to operate on the old data. However, during the transfer of data between the old software and the new software, usually the execution of the old software is fully stopped. One such example is described in xe2x80x9cRemote upgrading and updating of AXE10 softwarexe2x80x9d, pages 66-67, Ericsson Rev. No. 2, 1996, and relates to the transfer of variables in a record which are handled together in an iteration over all variables of the record.
In particular, usually variables to be transferred are identified through the designers of new software. Also, for each variable that must be converted, a respective conversion program must be prepared. This conversion program then executes the necessary transformations and transfers the result to the newly installed software.
However, the disadvantage with the above described solution is that the overall characteristics and performance of the system is deteriorated. In particular, during the data transfer, the execution of software is stopped in order to get a consistent copy of data of the old software.
Therefore, in U.S. Pat. No. 5,155,837 it is proposed to switch the input of data for new services to the new software in a first step. Further, when the service in progress in the old software is completed, the output of data from the services is switched from the old version to the new version. However, this solution may only handle software that handles services with a very short duration since the software according to the old version must first be finished before the new software version is fully operative.
In view of the above, the object of the invention is to achieve a disturbance free update for software with improved efficiency.
According to the invention, this object is achieved with a software processing device of the type with update functionality comprising memory means subdivided into a first memory partition storing a first group of software modules and related data, and a second memory partition storing a second group of software modules and related data, software update means adapted to load software and related data into the first memory partition while simultaneously continuing software processing with software stored in the second memory partition. The execution of software is instantly switched over to the new memory partition as soon as the same state for the newly loaded and the executing software is achieved.
Overall, to achieve a highly efficient and disturbance-free update of software modules even if there prevails old software that handles services with long duration, according to the invention it is proposed to update the new software with all necessary data of the old software while the old software is continuously executed. Immediately when data of the new software has reached the same state as data of the old software, the new software is taking over execution of the related functionality.
Further, according to a preferred embodiment of the invention, the software update means comprises update control means adapted to evaluate whether software in the newly loaded memory partition and the executing memory partition have reached a state to switch over execution of software. Preferably, the software update means further comprises interface and conversion means to load software and related data through the data transfer between different memory partitions in the software processing device. Also, preferably, the interface and conversion means carries out the transfer of software in a single background process and carries out the transfer of related data in a plurality of background processes. The single background process and the plurality of background processes are executed simultaneously with the execution of currently installed software.
Thus, to take care of the transfer of all necessary data related to different software at least one background process is run that handles all data pointed out to be transferred. Here, the background process either transfers the data to the new software unchanged or starts a conversion program, if necessary.
Since according to the invention the execution of software continues while the background process is running, data already being transferred may be changed through the old software. To achieve consistent data between the old and new software each such change of a variable is again transferred to the new software. In other words, at each write of already copied data through the old software the data is again transferred to the new software. In the case of data to be converted further a conversion program is started for this data and the conversion output is again transferred to the new software.
Therefore, according to the present invention it is possible to get all necessary data for the old software transferred to the new software without loosing any service already established through the execution of old software and without stopping the establishment of services during the transfer of data or during any other time. In particular, the transfer of data may involve the conversion of data to the representation and data structures of the new software.
Therefore, according to the present invention it is possible to heavily reduce the disturbance in case a functionality change is executed. Thus, a function change may be executed during normal working hours instead of during the night. Service providers of the software do not loose any revenue by doing an upgrade and subscribers to services provided by the software will not experience any deteriorated service.
Further, according to the present invention software updates may be added more frequently to the system since the costs for doing so are significantly reduced. Also, new features may be offered earlier to subscribers.
The same advantages are achieved with the inventive method for updating software comprising the steps loading new software and transferring all data used by the old software and the new software while execution of the old software is continued, evaluating whether the data of the new software has reached the same state as the data of the old software, and instantly switching the service to the new software as far as the state of data for the new software and the old software is equal.
According to a preferred embodiment of the inventive method, the data to be transferred is identified in at least one background process while the old software is continuously executed. Preferably, this background process is executed repeatedly to transfer variable rewritten during the execution of the software.
Also, according to yet another preferred embodiment of the inventive method the repeated execution of the at least one background process comprises the sub-steps marking a variable to be transferred each time it is rewritten by the old software, repeating the background process only for marked variables, and removing marks of transferred variables.
Thus, according to the inventive method potentially inconsistent variables are marked in a way that the marking is started at the same time as the background process starts. In particular, each data item to be transferred and that is written by the old software during the execution of the old software is marked. When the background process has scanned all data to be transferred it is started again but now only on the variables being marked to be transferred. After a transfer the marking of a data item is then cleared. Then again all variables that are written by the old software after the start of the second turn of the background process are marked. This loop continues until the number of rewritten marked variables during a turn of the background process does not decrease compared to the previous turn. Then, the remaining few variables may be transferred during a processing stop. In case such a processing stop is necessary the time therefor is minimized so as to achieve the maximum efficiency possible.
Also, both the inventive software processing device and the inventive method may be used within a plurality of applications, e.g., the upgrading of software within central processing units of mobile communication systems, the upgrade of a data base within minimal disturbance in case of a change of the structure of the data base, or the update of an operating system, respectively.